return [ n ]
       Causes  a  shell  function or . script to return to
       the invoking script with the return  status  speci-
       fied  by  n.  If n is omitted, the return status is
       that of the last command executed.

       If return was executed from a  trap  in  a  TRAPNAL
       function,  the  effect  is  different  for zero and
       non-zero return status.  With zero status (or after
       an  implicit  return  at  the end of the trap), the
       shell will return to  whatever  it  was  previously
       processing;  with a non-zero status, the shell will
       behave as interrupted except that the return status
       of  the  trap  is  retained.  Note that the numeric
       value of the signal which caused the trap is passed
       as  the  first  argument,  so the statement `return
       $((128+$1))' will return the same status as if  the
       signal had not been trapped.
